SYSTEMS AND METHODS FOR CONTROLLING THE MOVEMENT OF MATERIAL HANDLING VEHICLES BASED ON OBJECT DETECTION SYSTEMS

Abstract

The systems and methods provide a travel control system to enhance a material handling vehicle's object detection system. Speed ​​limits can be calculated for material handling vehicles based on the vehicle's characteristics and the field of view of the vehicle's object detection systems. For specific turning angles or turning angle ranges, the material handling vehicle's speed can be limited to ensure the vehicle can stop before encountering a newly detected object that was previously outside the object detection system's field of view.

Description

SYSTEMS AND METHODS FOR CONTROLLING THE MOVEMENT OF MATERIAL HANDLING VEHICLES BASED ON OBJECT DETECTION SYSTEMS CROSS REFERENCE TO RELATED APPLICATIONS This application is based upon, claims priority upon, and incorporates herein in its entirety by modality, United States Provisional Patent Application No. 63 / 195,125, filed on May 31, 2021, and entitled Systems and Methods for Material Handling Vehicle Movement Control Based on Object Detection Systems. STATEMENT REGARDING FEDERALLY SPONSORED INVESTIGATION Not applicable. BACKGROUND For specific operating environments, some material handling vehicles employ object detection systems. An object detection system, as applied to a material handling vehicle, is a supplemental system that detects objects within its field of view and can adjust travel speed or other travel characteristics based on the objects detected in the vehicle's path. Such a supplemental system can serve as a training aid and monitoring tool. For certain types of manually operated vehicles, training requirements are mandated by various government agencies, laws, standards, and regulations. For example, the Occupational Safety and Health Administration (OSHA) of the U.S. Department of Labor requires employers to train and supervise operators of various types of material handling vehicles. Recertification is also required every three years. In some cases, the operator will be provided with refresher training on relevant topics as needed. In all cases, the operator maintains control of the material handling vehicle during any operation. Additionally, a warehouse manager maintains control of the material handling vehicle fleet within the warehouse environment. BRIEF COMPENDIUM This description refers in general to the movement control of material handling vehicles and, more specifically, to systems and methods for the movement control of material handling vehicles based on intrinsic aspects of the material handling vehicle and the object detection system of the material handling vehicle. In some respects, a travel control system can enhance a complementary object detection system of a material handling vehicle. The system may include a material handling vehicle, a steering angle sensor, a speed sensor, a motor control unit, and a processor. The processor can be operationally connected to the steering angle sensor, the speed sensor, and the motor control unit. The processor can be configured to determine, based on intrinsic information from the material handling vehicle, a first speed limit associated with a first breakover angle. The processor can receive a first steering angle from the steering angle sensor. The processor can receive a first vehicle speed from the speed sensor.When the first turning angle exceeds the first break point angle, and the first speed exceeds the first speed limit, the processor can generate a signal to the motor control unit to decrease the speed of the material handling vehicle. In some respects, a method in a computer-implemented system for controlling the movement of a material handling vehicle may include receiving intrinsic aspects of the material handling vehicle into a control system. Based on these intrinsic aspects and a configuration of a scanner mounted on the material handling vehicle, at least one speed limit associated with at least one turning angle range of the material handling vehicle can be determined. The control system may receive the vehicle's speed. The control system may also receive the vehicle's current turning angle.When the current turning angle is within at least one turning angle range and the current speed exceeds at least one speed limit associated with at least one turning angle range, a signal can be generated to an engine control unit to reduce the speed of the material handling vehicle. In some respects, a computerized control system for a material handling vehicle may include an object detection system for the material handling vehicle. The material handling vehicle may include at least one scanner with a defined field of view between a first boundary and a second boundary. The material handling vehicle may further include a motor control unit, one or more processors, and a memory that stores one or more programs for execution by one or more processors. The one or more programs may include instructions for implementing a method to control a trip of the material handling vehicle. ML / t / ZUZZ / UOUUÓ 1 may include receiving the current speed and turning angle of the material handling vehicle into one or more processors. Based, at least in part, on the current speed and turning angle, the braking distance of the material handling vehicle can be determined. The method can determine if the stopping distance is within the scanner's field of view. If the braking distance is outside the scanner's field of view, a signal can be generated to the engine control unit to reduce the speed of the material handling vehicle. The foregoing and other aspects and advantages of the disclosure will become apparent from the following description. The description refers to the accompanying drawings, which form part of it and which illustrate a preferred configuration of the description. However, this configuration does not necessarily represent the full scope of the disclosure, and therefore, reference is made to the claims and to the text hereof to interpret the scope of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood, and its features, aspects, and advantages, distinct from those previously described, will become apparent when the following detailed description is considered. This detailed description refers to the following drawings. Fig. 1 is a left front side perspective view of a material handling vehicle according to aspects of this disclosure. Fig. 2 is a plan view of the material handling vehicle in Fig. 1. Figures 3A and 3B show an exemplary object detection system and the associated scanner viewing angle in accordance with aspects of the present description. Figures 4A and 4B show an exemplary object detection system and the associated scanner viewing angle in accordance with aspects of the present description. Figure 5 is a flow diagram of a displacement control system according to aspects of this disclosure. Figure 6 is a schematic block diagram of a computer system for implementing the system in Figure 5, which illustrates a non-limiting configuration. Figure 7 is an input-output diagram showing an exemplary algorithm for determining the speed limits of a material handling vehicle based on the turning angle. Fig. 8 illustrates exemplary intrinsic aspects of a material handling vehicle, according to aspects of the present description. ML / t / ZUZZ / UOUUÓ 1 Fig. 9 illustrates an exemplary travel route and braking distance of the material handling vehicle shown in Figs. 1-4B, according to aspects of this disclosure. Fig. 10 illustrates an exemplary scanner field and viewing angle of the material handling vehicle scanner shown in Figs. 1-4B according to aspects of this disclosure. Fig. 11 illustrates concentric circles associated with a pivot steering maneuver of the material handling vehicle shown in Figs. 1-4B according to aspects of this disclosure. DETAILED DESCRIPTION Before explaining any aspect of the invention in detail, it should be understood that the invention is not limited in its application to the construction details and arrangement of components set forth in the following description or illustrated in the following drawings. The invention is susceptible to other aspects and may be practiced or carried out in various ways. Furthermore, it should be understood that the phraseology and terminology used herein are for descriptive purposes and should not be considered limiting. The use of "includes," "comprises," or "has" and variations thereof in this document is intended to encompass the elements listed below and their equivalents, as well as additional elements. Unless otherwise specified or limited, the terms "mounted," "connected," "supported," and "coupled" and variations thereof are used broadly and encompass both direct and indirect assemblies, connections, supports, and couplings.Furthermore, connected and coupled are not limited to physical or mechanical connections or couplings. The following discussion is presented to enable a person skilled in the art to make and use embodiments of the invention. Several modifications to the illustrated embodiments will be readily apparent to those skilled in the art, and the generic principles herein may be applied to other embodiments and applications without departing from the embodiments of the invention. Therefore, the embodiments of the invention are not intended to be limited to the embodiments shown, but should be given the broadest scope compatible with the principles and features described herein. The following detailed description should be read with reference to the figures, in which similar elements in different figures have similar embodiment numbers. The figures, which are not necessarily to scale, represent selected embodiments and are not intended to limit the scope of the embodiments of the invention.Those skilled in the technique will recognize that the examples provided here have many useful alternatives. ML / t / ZUZZ / UOUUÓ 1 and fall within the scope of the modalities of the invention. It should also be appreciated that material handling vehicles are designed in a variety of classes and configurations to perform a variety of tasks. It will be evident to those skilled in the art that the present description is not limited to any specific material handling vehicle and can also be provided with various other types, classes, and configurations of material handling vehicles, including, for example, forklifts, pallet trucks, reach trucks, SWING REACH® vehicles, turret trucks, side-loading trucks, counterbalance forklifts, pallet stackers, order pickers, transtackers, and man-on trucks, and can be commonly found in warehouses, factories, shipping yards, and, in general, wherever pallets, large packages, or loads of goods need to be moved from one place to another.The various systems and methods described in this document are suitable for any of the material handling vehicles controlled by an operator, controlled by pedestrians, remotely controlled, and autonomously controlled. The modalities described may include an object detection system to provide onboard object detection for the material handling vehicle. The object detection system can enhance and reinforce operator training and supervision in a manned material handling vehicle. The object detection system may include an onboard object detection unit and a processing unit to initiate inputs from the material handling vehicle operator as a training aid and potentially control the functionality of the material handling vehicle under defined operating conditions. In some modalities, the processing unit may comprise a telematics system, for example, The Raymond Corporation's WAREHOUSE® Material Handling Vehicle Fleet Management System. The object detection system can serve as a training reinforcement tool to, among other things, provide warnings about the proximity of a material handling vehicle to other objects, consistent with the customer's facility rules in the warehouse environment. It is not intended to replace the training requirements that an operator always look in the direction of travel, be aware of their proximity to other objects at all times, assume and maintain a proper operator position, and follow various aspects of their operator training. ML / t / ZUZZ / UOUUÓ 1 The object detection system can use a scanner (also called a sensor) to detect objects within a warehouse, for example, inside and outside aisles, while the material handling vehicle (MV) is traveling in the tractor-led direction, and in some configurations, while the MV is traveling in the forklift-led direction. If an object is detected, the MV equipped with the object detection system can provide an indication to the operator, such as displaying "Sensor Stop" on the MV's operator display, sounding an audible tone, and / or initiating haptic feedback, or any combination thereof. The indication(s) to the operator can be provided at various levels; for example, a message may be displayed first, then an audible tone may sound, and then haptic feedback may be initiated.One or more of these prompts can be initiated for the operator, allowing them to command the material handling vehicle to slow down or stop based on the distance to the detected object. If no action is taken, the material handling vehicle will systematically enter a similar state (slow or stopped). If the material handling vehicle slows down or stops, not all prompts to the operator may be initiated. For example, if the material handling vehicle slows down or stops before haptic feedback is provided, the operator may not receive haptic feedback. The operator will maintain full control of the material handling vehicle equipped with an object detection system at all times. In some scenarios, a warehouse management system or facility manager, in fulfilling their duty to oversee the operation of their forklift fleet, may adjust the object detection system's functionality to meet the specific operating conditions at their facility. For example, the facility manager could set a minimum and maximum desired speed for the object detection system to use when it detects an object, initiating a slower travel speed. In some configurations, the scanner may be a two-dimensional scanner. In some configurations, the scanner may have more than one detection field. In some configurations, more than one scanner may be included to provide more than one detection field. Therefore, the scanner may be a primary scanner, and the object detection system may further include a secondary scanner, a tertiary scanner, or any number of scanners to achieve a desired combined field of view for the object detection system. In some configurations, a three-dimensional scanner may be used. In some configurations, a spatial scanner may be used. Each of the various scanner options may be used in any combination and may allow the scanner or scanners to be configured using software tools supported by the scanner vendor. In some configurations, the object detection system may implement various types of scanners, including the R2100 (multi-beam LED scanner (2D LiDAR sensor)), the SICK TIM 781-2174101 2D LiDAR sensor or similar, and radar, as examples. In some configurations, the object detection system using any of the aforementioned scanner types may support The Raymond Corporation's rPORT™ technology, which enables an open architecture with a standardized interface. In other configurations, a discrete I / O implementation may also be used. In some configurations, the raw data from the object detection system can be processed to produce granularity that can improve the accuracy and performance of the object detection system compared to conventional scanning systems. This can provide a more robust object detection system than conventional systems that rely on processing provided by a scanner vendor. For example, in a given field of view, the described scanner can detect fields that correspond to a speed of 0 to 9 miles per hour at intervals of tenths of a mile and can scan sections of the field of view at intervals of hundredths of a degree.Therefore, fields can be generated for a scanner to detect an object more accurately, and the number of possible fields can be the product of the number of angular sections in hundredths of a degree of the viewing angle and the number of speed intervals (e.g., 10 times 9). In addition to, or instead of, the possible location of the scanner as shown in the various figures, the scanner(s) can be mounted in various locations on the material handling vehicle. This description can serve as a training supplement for operator-driven material handling vehicles. It can also enhance the functionality of a complementary object detection system in a manned or unmanned material handling vehicle by controlling components that affect the vehicle's travel based on intrinsic aspects of the material handling vehicle and / or its operating environment. Intrinsic aspects of a material handling vehicle may include, but are not limited to, the vehicle's weight, height, width, drive wheel locations, and non-drive wheel locations.The intrinsic aspects of an object detection system in a material handling vehicle may include the detection range, detection viewing angle, detection height, shape of the detection zone, and physical position of the scanner, as non-limiting examples. A travel control system can be integrated with the complementary object detection system as an object detection augmentation, and can help control any combination of aspects of vehicle travel, including speed, turning angle, load handling devices and accessories, and / or mast height, based on intrinsic aspects of the object detection system on the material handling vehicle, including detection range, detection viewing angle, detection height, shape of the detection zone, and physical position of the scanner. In some configurations, the travel control system can distinguish between a vehicle handling materials that rotate on or around a point. The pivot behavior can be customized to allow maneuverability with the travel control system. Figures 1 and 2 illustrate a non-limiting example of a material handling vehicle 10 in accordance with this disclosure. The material handling vehicle 10 may include a vehicle frame 12, a steerable drive wheel 14, a fixed axle 16, a power section 18, and an operator compartment 20. The power section 18 may be disposed within the vehicle frame 12 and may include a battery (or other power source) configured to supply power to various components of the material handling vehicle 10. For example, a battery may supply power to a motor (not shown) and / or transmission (not shown) disposed within the power section 18 and configured to drive the drive wheel 14. In the non-limiting example illustrated, the drive wheel 14 is disposed below the power section 18.In other non-limiting examples, the drive wheel(s) 14 may be arranged in another location under the vehicle frame 12. The operator compartment 20 may include a control handle 22 configured to provide a user interface for an operator and to allow the operator to control the speed and direction of travel of the material handling vehicle 10. In some non-limiting examples, the control handle 22 may be configured to manually steer and control the power of the drive wheel 14. In the non-limiting example illustrated in Figs. 1 and 2, the material handling vehicle 10 includes ML / t / ZUZZ / UOUUÓ 1 A pair of 24 forks configured to engage loads (e.g., a pallet). The 24 forks can be raised and lowered by an actuator (not shown) to lift / place loads. In some non-limiting examples, the forks can be attached to a mast and raised or lowered by actuators in response to commands from a control handle. The material handling vehicle 10 can be operated by an operator and may be capable of picking, placing, transporting, or otherwise manipulating a load, possibly including a pallet. In several examples, the operator controls the material handling vehicle 10 so that the forks 24 engage a pallet carrying a load. By doing so, the operator can extend or retract the actuators (not shown) to pick, place, engage, or otherwise manipulate the load. Once the load is positioned on the forks 24, the operator can move the load to another location as required. In some non-limiting examples, a human operator may be replaced by an automated controller to comprise a fully automated system (i.e., an autonomously guided material handling vehicle). Material handling vehicles, including the material handling vehicle 10 illustrated in Figs. 1 and 2, may include systems for detecting objects in a travel path. These systems may include scanners, which may have a defined field of view and be able to search for objects within that field of view. Referring to Figs. 3A and 3B, a preferred embodiment of a material handling vehicle 100 with an object detection system 110 is shown, the material handling vehicle 100 being generally similar to material handling vehicle 10. The object detection system 110 may include a mounting plate 112 and a scanner 114, which, in the illustrated embodiment, comprises a LiDAR scanner 114. The object detection system 110 may be positioned on a material handling vehicle in a manner that is advantageous for detecting objects that may impede the vehicle's travel.As illustrated, for example, the object detection system 110 is positioned on a lower portion 116 of a front side 118 of the material handling vehicle 100, the front side 118 being the side of the material handling vehicle 100 facing a set of forks 120. In some embodiments, a material handling vehicle may travel primarily in a tractor-first direction, with a front side of the material handling vehicle generally facing in the direction of travel, and the forks of the material handling vehicle extending in a direction opposite to the direction of travel. Thus, in the illustrated embodiment, the LiDAR scanner 114, being mounted on the front side 118, can scan an area in the direction of travel of the material handling vehicle. ML / t / ZUZZ / UOUUÓ 1 Being mounted on the underside 116, the LiDAR scanner 114 is advantageously positioned to detect objects or obstructions along the floor surface that might otherwise go unnoticed if the scanner 114 were mounted higher on the material handling vehicle 100. The LiDAR scanner 114 can be housed within the lower part 116, and the mounting plate 112 can provide a protective cover for the scanner 114. As illustrated in Fig. 3B, the mounting plate can define a cutout 122, which can provide a window through which the scanner 114 can scan the environment of the material handling vehicle 100. The scanner 114 can have a maximum viewing angle A between a first limit 126 and a second limit 128, which can depend on the internal location of the scanner 114 in combination with the dimensions of the cutout 122 and can further define a field of view 124. In some configurations, the viewing angle A can be up to approximately 110 degrees, or up to approximately 120 degrees, or up to approximately 130 degrees.In some configurations where the material handling vehicle includes more than one scanner and therefore more than one scanner field of view, the scanner field data can be combined and used in a travel control system (e.g., travel control system 200 shown in Fig. 5) to calculate a permitted or non-permitted travel route for a material handling vehicle. In other embodiments, including as illustrated in Figs. 4A and 4B, a scanner or LiDAR can be mounted on a material handling vehicle in other configurations, which can, for example, increase the scanner's field of view. As illustrated, a material handling vehicle 100 can include a scanner assembly 130, which can be mounted on a lower portion 116 of the material handling vehicle 100, along a front face. The scanner assembly 130 can extend outward from the lower portion 116 by a distance D1. A scanner 132 can be mounted within the assembly 130 and can scan an area in front of and to the sides of the scanner 132. Thus, the scanner 132 could have a viewing angle B greater than the viewing angle A and defines a field of view 134 that has a larger area than the field of view 124. In some configurations, the viewing angle B can be greater than 180 degrees. When the trajectory of a material handling vehicle changes, such as when the turning angle changes, the field of view of an object detection sensor or scanner on the vehicle may also change. In some cases, a change in the turning angle of a material handling vehicle can bring a previously undetected object into its path. In some instances, without system correction, the material handling vehicle may travel too fast to avoid contact with the undetected object. Furthermore, when the field of view changes, an object detection system may require some time to scan the new field of view for objects that could obstruct its path.Therefore, systems can be provided for a material handling vehicle that can limit the speed of the material handling vehicle in response to a change in trajectory, to mitigate possible contact with previously undetected objects. Figure 5 illustrates an exemplary embodiment of a travel control system 200 for a material handling vehicle (e.g., material handling vehicles 10, 100), which can be implemented by a control system 150 (e.g., as shown in Figure 6) of the material handling vehicle 100. As will be described, the travel control system 200 can calculate speed limits based on the properties of a material handling vehicle and defines potential and permitted travel paths for the material handling vehicle. The process can begin at step 202, with a material handling vehicle being activated. At this step, one or more processes can be initiated to drive the operation of the material handling vehicle. For example, a material handling vehicle engine can be started, a start-up sequence for a control system can be initiated, and so on. In step 204, the properties of a material handling vehicle can be obtained. The information obtained in step 204 may include physical properties of the material handling vehicle 100 and can be used to determine the speed limits, permitted routes, and prohibited routes of the material handling vehicle 100 for different dynamic conditions, such as a turning angle or a range of turning angles. For example, the information may include intrinsic aspects of the material handling vehicle 100, which may include, but are not limited to, the vehicle's weight, height, width, drive wheel locations, and non-drive wheel locations. This information can be received by a processor 152 of the material handling vehicle's control system 150 and used to calculate the maximum speed limits for different operating conditions of the material handling vehicle.Figure 6, for example, illustrates an exemplary communication system 300 for computer elements that can enable the control system 150 of the material handling vehicle 100 to obtain information about the material handling vehicle from a memory 160 of the control system 150, or from a remote computer system 304. ML / t / ZUZZ / UOUUÓ 1 As illustrated in Fig. 6, the material handling vehicle 100 may include the control system 150, which may include a processor 152, a display 154, one or more inputs 156, one or more communication systems 158, and / or memory 160. The control system may also include the scanner 114, speed sensors 162, steering angle sensors 164, and a motor control unit 166. In some embodiments, the processor 152 may be any suitable hardware processor or a combination of processors, such as a central processing unit (CPU), a graphics processing unit (GPU), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), etc. In some embodiments, the display 154 may include any suitable display device, such as a computer monitor, a touchscreen, a television, etc.In some modes, the 156 inputs may include any suitable input device and / or sensor that can be used to receive user input, such as a keyboard, mouse, touch screen, microphone, camera, etc. In some configurations, communication systems 158 may include any hardware, firmware, and / or software suitable for communicating information over the communication network 302 and / or any other suitable communication network. For example, communication systems 158 may include one or more transceivers, one or more communication chips and / or chipsets, etc. More specifically, communication systems 158 may include hardware, firmware, and / or software that can be used to establish a Wi-Fi connection, a Bluetooth connection, a cellular connection, an Ethernet connection, etc. In some embodiments, memory 160 may include any suitable storage device or devices that can be used to store instructions, values, etc., that can be used, for example, by the processor 152. Memory 160 may include any suitable volatile memory, non-volatile memory, storage, or any suitable combination thereof. For example, memory 160 may include random-access memory (RAM), read-only memory (ROM), electronically erasable programmable read-only memory (EEPROM), one or more flash drives, one or more hard disks, one or more state units, one or more optical drives, etc. In some embodiments, memory 260 may have a computer program coded in it to control the operation of the material handling vehicle 100, including implementing all or part of the travel control system 200 illustrated in Fig. 5.Information, including the intrinsic properties of the material handling vehicle 100, can be static and can be stored in the memory 160 of the material handling vehicle, and can be provided to the processor 152 for calculation of the. ML / t / ZUZZ / UOUUÓ 1 speed limit tables. In other modalities, some information from the material handling vehicle 100 that will be used to calculate speed limits may be dynamic information that can be obtained through sensors on the material handling vehicle. For example, a weight sensor or sensors (not shown) may be provided for a material handling vehicle, or for a material handling vehicle load, and may be used to calculate a braking distance for the material handling vehicle. In some embodiments, the sensing elements and control units of the material handling vehicle may be operationally integrated into the control system 150. For example, a control system 150 may include steering angle sensors 164 to detect the vehicle's current steering angle, and the steering angle sensor 164 may produce a signal indicative of a steering angle that can be provided to the processor 152. In some embodiments, the steering angle may be detected via a sensor 164 in a steering element (e.g., the control handle 22 of the material handling vehicle 10). The sensor 164 may be any sensor known in the art for measuring a vehicle's steering angle, which, in some non-limiting examples, may include gyroscopes or accelerometers.In other embodiments, a turning angle can be calculated from the orientation of the material handling vehicle 100, which can be obtained through visual sensors, such as cameras. Speed ​​sensors 162 can also be provided for the material handling vehicle to detect a speed and communicate that speed to the processor 152. The speed sensor 162 can be any sensor known in the art for measuring the speed of a vehicle, including, but not limited to, accelerometers or gyroscopes. A motor control unit 166 can be provided in the control system 150. The motor control unit 166 can be in communication with the processor 152 and can reduce the speed of a motor of the material handling vehicle 100 or set a speed limit on the material handling vehicle 100 based on a signal received from 152. The elements of the control system 150 can communicate using standardized communication protocols. For example, the elements of a control system 150 can communicate via a controller area network (CAN) bus 168, which can provide communication between elements without requiring specific wired connections between each element communicating with other elements of the control system 250. Messages can be provided from a given element to the CAN bus 168, to which each of the other elements is connected, and the messages can be formatted for consumption by the element for which they are intended. Therefore, signals between elements, for example, signals from the scanner 114 to the processor 152, or from the processor 152 to the motor control unit 166, can be contained within a message provided on the CAN bus 168. In some embodiments, the control system 150 can be operationally connected to the computing device 304 via a communications network 302. In some embodiments, the communications network 302 can be a local area network, a wide area network, etc. The computing device 304 can include the processor 306, the display 308, the inputs 310, the communication system 312, and the memory 314, which can be similar to the corresponding components of the control device 150. The memory 314 can include persistent memory that can store information about a material handling vehicle (e.g., material handling vehicle 100) or multiple material handling vehicles. Upon a request (e.g.Upon receiving a request in communication system 312, the computing device 304 can return information to the material handling vehicle 100 control system 150 for use in the material handling vehicle 100 object detection systems. This information can be provided to the processor 152 directly via the CAN bus 168. Additionally or alternatively, the information can be provided from communication system 158 to memory 160 via messages sent over the CAN bus 168. Returning to Figure 5, in step 206, a material handling vehicle 100 speed can be temporarily restricted until the travel control system 200 can generate a speed limit table. As shown, the temporary speed limit can be 1 mile per hour, but other configurations are possible. For example, in some modes, a temporary speed limit for a material handling vehicle could be approximately 0 km / h (0 mph), 3.2186 km / h (2 mph), or 4.8280 km / h (3 mph). The temporary speed limit could be set by a facility manager, for example, through inputs 156 of the control system 150. In other modes, the temporary speed limit could be hardcoded in memory 160 and can be included in the material handling vehicle information received in step 204. Referring again to Fig. 5, in step 208, the travel control system 200, upon starting the material handling vehicle, can generate a table of maximum speed limits for the material handling vehicle 100 when the material handling vehicle 100 is steered at a given angle or within a given range of angles. These speed limits can be generated to minimize potential contact with objects that may not be in the field of view of a material handling vehicle scanner. For example, a speed that is permissible in a first direction of travel may cause the material handling vehicle 100 to make contact with an object outside the field of view 124 if that speed is maintained when the material handling vehicle is steered along a path outside the previous field of view 124.Below is a representative, non-limiting table of generated speed limits. The turning angles shown are absolute values, and therefore the associated speed limits would apply to the corresponding negative turning angle. SPEED LIMIT - TURNING ANGLE 8.0467 km / h (5.0 mph) - 10 degrees 6.4373 km / h (4.0 mph) - 20 degrees 4.8280 km / h (3.0 mph) - 30 degrees 3.2186 km / h (2.0 mph) - 40 degrees 1.6093 km / h (1.0 mph) - 50 degrees 4.8280 km / h (3.0 mph) - 75 degrees (Pivot) Speed ​​limits for a material handling vehicle can be generated for certain dynamic conditions of the material handling vehicle, including the turning angle. Although limiting the speed of a material handling vehicle may increase the vehicle's path travel time, the speed limit can allow a scanner (e.g., scanner 114) sufficient time to react to an object during a steering maneuver. As illustrated in the input-output diagram in Fig. 7, the travel control system 200 can implement an algorithm 350, which can receive inputs for a material handling vehicle dynamics model 352, a scanner location and field of view 354, a desired stopping distance from an object 356, and desired turning angle cut-off points 358, and can generate speed limits as a function of the angle 360 ​​(e.g., as shown in the representative generated speed limit table shown above). The material handling vehicle dynamics model input in 352 may include material handling information obtained in step 204 of the 200 travel control system. For example, determining a speed limit for a given turning angle may require calculating a vehicle trajectory to determine the probability of a material handling vehicle part coming into contact with an object. ML / t / ZUZZ / UOUUÓ 1 With reference to Fig. 8, the speed limits described will vary depending on the type of material handling vehicle and may depend on intrinsic aspects of the material handling vehicle (e.g., information received from the material handling vehicle in step 204). For a self-steering material handling vehicle, as a non-limiting example, a travel path can be represented as two concentric circles, representing two selected edges of the material handling vehicle. The exemplary selected edges of the self-steering material handling vehicle 100 are reflected in Fig. 7 at points 140 and 142, which can be positioned on opposite sides of the material handling vehicle 100. In a turning operation, point 140 can travel along a circumference 141 of a circle of radius R1, and point 142 can travel along a circumference 143 of a concentric circle of radius R2.Collectively, the circumference 141 of the first circle and the circumference 143 of the second circle can define a projected path 146 of the material handling vehicle. The geometric properties of the concentric circle representing the travel path of the respective points 140, 142 can be used in a calculation to determine the projected path 146 of the vehicle 100. The projected path can then be used to calculate a speed limit for the material handling vehicle 100. For example, a speed limit can be determined to ensure that the projected path does not coincide with or intersect a prohibited travel path, based on other factors (e.g., a combination of inputs 354, 356, 368). The dimensions of the material handling vehicle 100 can be combined with other aspects of the material handling vehicle 100 in a dynamic model to calculate a speed limit for the material handling vehicle for a given turning angle or range of turning angles. In some embodiments, a speed limit for a given turning angle can be determined in part based on a stopping distance for a given trajectory. In this regard, Figure 9 illustrates a projected trajectory 170 of the material handling vehicle 100, which, as shown, is traveling at a speed of 75.6392 km / h (4.7 mph) with a turning angle of 13 degrees. Line 172 illustrates a stopping distance, which is the distance at which the material handling vehicle 100 could safely stop given an initial trajectory, position, and turning angle of the vehicle.A heavier material handling vehicle may also have a longer braking distance, as it may require more energy to slow down, while a lighter vehicle would have a shorter braking distance. Braking distance 172 can be taken into account when calculating a material handling vehicle's speed limit for different turning angles, as reducing the vehicle's speed is crucial. ML / t / ZUZZ / UOUUÓ 1 100 can provide an object detection system time 110 to adjust to scan the new direction of travel, while ensuring that vehicle 100 does not travel at a speed that is likely to cause contact with a newly discovered object. In some modalities, the scanner's location, field of view, and range can also be used as input to determine speed limits for a material handling vehicle. In this regard, Figure 10 illustrates a projected travel path 170A of the material handling vehicle 100, which, as illustrated, includes a permitted portion 174 and a prohibited portion 176. The permitted portion 174 can be a portion of the route 170A that is within the field of view of the combined scanner 124 (e.g., between the first boundary 126 and the second boundary 128), which can be determined by a position of the scanner 114 on the vehicle, a configuration of the scanner (e.g., within the lower portion 116 of the material handling vehicle 100 illustrated in Figures 3A and 3B, or mounted outside a lower portion 116 of the material handling vehicle 100 on a scanner assembly 130 as shown in Figures 4A and 4B), the number of scanners, etc.A speed limit can be calculated for a given turning angle to ensure that the projected braking distance of the material handling vehicle 100 is within the permitted portion 174 and not in the non-permitted portion 176. Therefore, the speed limit for a given turning angle can guarantee that vehicle 100 can stop before contact with an object that was previously outside the field of view of scanner 124. Returning to Figure 7, the algorithm 350 for determining a speed limit based on a turning angle 360 ​​can also take as input a desired stopping distance from an object 356. For example, a speed limit can be determined to ensure that a material handling vehicle can stop at a predetermined distance from an object that might fall outside the field of view of a scanner. With reference to Figure 9, a speed limit can be determined for the material handling vehicle 100 traveling at a given turning angle to ensure that the material handling vehicle can stop at a buffer distance D2 from the limit 128.Therefore, the braking distance of the material handling vehicle can be set to the distance to the boundary 128 for a given turning angle, minus the distance D2, and a speed can be selected to achieve this braking distance given the buffer distance D2. It can therefore be assumed that the area outside the scanner's field of view 124 includes objects that may impede travel. In some modes, the buffer distance D2 can be set as the default, while in others, it could be configured by a user (e.g., a facility manager). The buffer distance D2 can be measured as the minimum distance between a field of view boundary (e.g., boundaries 126, 128) and the point along the projected vehicle path 170 that is closest to the boundary 126, 128 that would intersect the material handling vehicle's projected path 170. In some modes, a speed limit calculated for the speed in the direction algorithm 350 can be calculated according to a series of equations that can use inputs 352, 354, 356, and 358. For example, a first equation or set of equations representing the travel paths of points 140 and 144 along the arcs of concentric circles can have a general form RA2. The viewing angle of the combined scanner A can be constrained in a second equation or set of equations, which may include one or more linear equations. Solving the first equation and inserting the results into the second equation can produce a third equation, which is a quadratic equation. Aspects of the third equation can represent the point of intersection of the travel path and the scanner's viewing angle (e.g., viewing angles of scanners A and / or B).A fourth equation can represent a line drawn from the material handling vehicle's mode location to the point of intersection with a boundary (e.g., boundaries 126, 128), with the magnitude or length of the line representing the derived stopping distance for a given turning angle. The braking distance (e.g., a distance from the material handling vehicle 100 to the braking distance 172) can be expressed in a fifth equation, which is in quadratic form. Aspects of the fifth equation can represent a speed limit for the material handling vehicle for a given turning angle. As shown in Fig. 7, the desired turning angle breakpoints 358 can be included as input to the speed algorithm in direction 350. A speed limit for a material handling vehicle can be set for at least one turning angle range or a plurality of turning angle ranges, and the turning angle breakpoints can be the limits of these ranges. For example, as shown in the representative speed limit table above, in some configurations, the turning angle breakpoints can be defined as 10 degrees, 20 degrees, 30 degrees, 40 degrees, and 50 degrees respectively, and thus can define turning angle ranges of less than 10 degrees, 10–20 degrees, 30–40 degrees, 40–50 degrees, and more than 50 degrees respectively. In other configurations, a user could select different breakpoint angles and, alternatively, could select more or fewer breakpoint angles.As shown later in the representative table, a first speed limit can be applied when the material handling vehicle 100 is driven within the 10-20 degree range (e.g., 8.0467 km / h (5 mph)), and a different speed limit (e.g., 6.4373 km / h (4 mph)) can be imposed when the turning angle of the material handling vehicle 100 is within the 20-30 degree range. In some configurations, the break-point angles may be coded as default values ​​in a material handling vehicle's travel control system (e.g., in memory 160 of the control system 150). In other configurations, a user can select the desired break-point angles (e.g., using inputs 156 or 310 shown in Fig. 6). The speed output in the steering algorithm could be a table (e.g., the representative speed limit table shown above) which assigns speed limits to turning angle ranges of a material handling vehicle, based on inputs 352, 354, 356, and 358. In some modes, the material handling speed 100 can be reduced or limited based on communication from the processor 152 to the motor control unit 155 via the CAN bus 168, as shown in Fig. 6. In some configurations, a speed limit table for a movement control system may include speed limits associated with specific material handling vehicle maneuvers, and these speed limits may be static rather than algorithm-generated (e.g., algorithm 350). For example, two common steering maneuvers include right-angle turns (i.e., a 90-degree turn) and pivots (e.g., a 180-degree turn), as illustrated in Figure 11. Right-angle turns are commonly performed when turning into an aisle, exiting an aisle, and rounding a corner. Pivots are commonly performed when turning around outside an aisle, dropping off a load, and hooking up a load. As illustrated in Figure 9, a projected path 170B during a pivot maneuver can be narrowly circumscribed.Given the frequency with which this maneuver must be performed, and the lower probability of obstructing travel given a smaller projected path 170B, it may be impractical to impose a vehicle speed limit to allow scanner 114 to scan the area in the travel path, as this could be performed quickly by an operator. Limiting the speed for these maneuvers, according to algorithm 350, may thus increase travel time without reducing the speed limit. Therefore, in some modalities, a cutoff angle can be defined for a steering turn maneuver, which may allow the material handling vehicle 100 to proceed without limit. ML / t / ZUZZ / UOUUÓ 1 speed, or with a higher speed limit than that provided in algorithm 350 when performing maneuvers such as a right-angle turn or a pivot. Furthermore, a turning angle for a pivot or a right-angle turn may be less than 180 degrees or 90 degrees respectively, and therefore a 90-degree turn of the material handling vehicle 100 could be achieved by maintaining the travel at another turning angle for a period of time, until the material handling vehicle 100 is oriented at a 90-degree angle with respect to an initial position.For example, according to the representative table shown above, a 75-degree turning angle limit can be incorporated to allow the material handling vehicle 100 to travel (i.e., pivot) at a higher maximum speed when its turning angle exceeds a predefined pivot point. Thus, according to the representative table, the material handling vehicle 100 can travel at speeds up to 4.8280 km / h (3 mph) during a pivot operation when its turning angle exceeds 75 degrees. In some configurations, when the cut angle is detected, the speed limit can be higher than the speeds identified in the generated speed limit table. In some configurations, the pivot angle and associated speed limit can be included in the speed limit table.In some modes, a cut pivot angle and associated speed limit may be included in the material handling vehicle information provided in step 204 of the vehicle travel control system 200. In some modes, a material handling vehicle user may set a cut pivot angle and associated speed limit. Referring back to Fig. 5, the travel control system 200 may allow the material handling vehicle 100 to complete its journey in step 210, once the speed limit table has been generated in step 208. In other modes, the complete journey may be allowed before a speed limit table is generated, or during its generation. In still other modes, a material handling vehicle may not be allowed to travel until the speed limit table has been generated. The complete journey allows the material handling vehicle 100 to operate without the temporary restrictions imposed in step 206, for example, and may allow the material handling vehicle 100 to operate according to the speed limits generated in step 208. In step 212, the speed and turning angle of the material handling vehicle 100 can be sampled over a given time interval. The speed is ML / t / ZUZZ / UOUUÓ 1 can be obtained from sensors on a material handling vehicle, which may include, for example, accelerometers, gyroscopes, or other sensing devices known to those skilled in the art. The speed and turning angle of a material handling vehicle (e.g., material handling vehicle 100, 10) can be sampled or obtained at set time intervals. In some non-limiting examples, the speed and turning angle can be sampled once per millisecond, once every 10 milliseconds, once every 100 milliseconds, once every second, once every 5 seconds, or once every 10 seconds. In other modes, the speed and turning angle of a material handling vehicle can be sampled by completing steps 214, 216, 218, and 220. In some modes, a user can configure a probing or sampling interval. In step 214, the travel control process can assess whether the speed of material handling vehicle 100, obtained in step 212, exceeds the speed limit generated in step 208 for the material handling vehicle's current turning angle. When the speed of material handling vehicle 100 exceeds the speed limit for the material handling vehicle's current turning angle, the material handling vehicle's speed can be reduced in step 216. Reducing the material handling vehicle's speed can reduce the risk of contact with an object, as described above, and can also be beneficial by providing additional time for the scanner to adjust to the changed angle of material handling vehicle 100 and to search for additional potential objects in the material handling vehicle 100's path.The speed of material handling vehicle 100 can be reduced in predetermined increments (e.g., 0.16093 km / h (0.1 mph)), which can reduce the speed of material handling vehicle 100 without producing an unnecessarily awkward change in acceleration or deceleration. For example, using the representative speed limit table above, since material handling vehicle 100 is traveling at 8.0467 km / h (5 mph) and turns past the break point of + / - 10 degrees, the travel control system 200 can bring material handling vehicle 100 to the next speed set point (e.g., 6.4373 km / h (4 mph)) in predetermined increments, e.g., 0.16093 km / h (0.1 mph), thereby expanding the display range of the object sensor system.If the operator continues driving and increases the turning angle, the 200 travel control system can continue adjusting the material handling speed within the ranges specified in the speed limit table to maintain the maximum display range. In some modes, as shown in Fig. 5, even after slowing down in step 216, the vehicle system... ML / t / ZUZZ / UOUUÓ 1 displacement control 200 can retest the speed and turning angle of the material handling vehicle 100, and assess whether additional deceleration is required, or whether the trajectory of the material handling vehicle is within the speed limits generated in step 208. In other modes, if the speed of the material handling vehicle exceeds a speed limit for the current turning angle, the vehicle can be decelerated by an amount necessary to bring the speed of the material handling vehicle below the speed limit before the speed and turning angle are sampled again. If the speed of the material handling vehicle is below a speed limit for the given turning angle, the system analysis can be completed in step 218, and normal operation of the material handling vehicle 100 can be resumed in step 220. Normal operation may include unrestricted operation, for example, when the system does not reduce the speed of the material handling vehicle 100 or otherwise override the operating parameters of the material handling vehicle 100. In some configurations, the operation of material handling vehicle 100 may be stopped or paused if the system encounters error 222 and a step cannot be completed. For example, as shown in Fig. 5, if system 200 cannot obtain information from the material handling vehicle in step 204 to allow the system to generate the speed limit table in 208, this may constitute error 222, and the operation of the material handling vehicle could be prevented to ensure that material handling vehicle 100 cannot be operated without the object detection system properly calibrated. Upon error 222, system 200 may impose a waiting period in 224 before attempting to resume the process and start material handling vehicle 100 in step 202.In some modes, for example, the user of a material handling vehicle must wait a predetermined time before attempting to operate the material handling vehicle 100 again. In other modes, the system may automatically perform a retry operation after a specified time interval, which could be a system parameter that a user can configure, for example. Errors 222 can occur in other steps of the travel control system 200, including, for example, when speed and steering angle data are sampled in step 212. In some modes, an error can trigger other system responses. For example, when an error occurs, the material handling vehicle may be allowed to operate with a reduced speed limit for the vehicle (e.g., 1.6093 km / h (1 mph)). ML / t / ZUZZ / UOUUÓ 1 While various spatial and directional terms, such as top, background, bottom, middle, side, horizontal, vertical, front, and the like, may be used to describe examples in this description, it is understood that such terms are used simply with respect to the orientations shown in the drawings. Orientations may be reversed, rotated, or otherwise changed, so that a top becomes a bottom and vice versa, a horizontal becomes vertical, and so forth. Within this specification, the embodiments have been described in a manner that allows for a clear and concise specification, but it is intended and will be appreciated that the embodiments can be combined or separated in various ways without departing from the invention. For example, it will be appreciated that all the preferred features described herein are applicable to all aspects of the invention described herein. Therefore, although the invention has been described in relation to particular embodiments and examples, the invention is not necessarily so limited, and it is intended that many other embodiments, examples, uses, modifications, and deviations from the embodiments, examples, and uses are covered by the appended claims. The full description of each patent and publication cited herein is incorporated by embodiment, as if each such patent or publication were individually incorporated by embodiment herein. Several features and advantages of the invention are set forth in the following claims.

Claims

1. A displacement control system for improving a complementary object detection system of a material handling vehicle, the displacement control system being characterized in that it comprises: a material handling vehicle; a steering angle sensor; a speed sensor; a motor control unit; and a processor operatively connected to the steering angle sensor, the speed sensor, and the motor control unit, the processor being configured to: determine, based on intrinsic aspects of the material handling vehicle, a first speed limit associated with a first breakover angle; receive from the steering angle sensor, a first steering angle; receive, from the speed sensor, a first vehicle speed;and when the first turning angle exceeds the first critical point angle and the first speed exceeds the first speed limit, generate a signal to the engine control unit to decrease the speed of the material handling vehicle.

2. The displacement control system according to claim 1, characterized in that the processor is configured to determine a stopping distance of the material handling vehicle, based on intrinsic aspects, and wherein the first speed limit is determined, at least in part, based on the braking distance.

3. The displacement control system according to claim 2, characterized in that it further comprises a first scanner mounted on the material handling vehicle, the first scanner being configured to detect objects within a field of view, the field of view having a first limit and a second limit.

4. The displacement control system according to claim 3, characterized in that the stopping distance is within the field of view of the first scanner.

5. The displacement control system according to claim 3, characterized in that it further comprises a second scanner, wherein the field of view is a combination of a field of view of the first scanner and a field of view of the second scanner.

6. The displacement control system of claim 1, characterized in that the first break point angle is one of a plurality of break point angles, and wherein a speed limit is determined for each of the plurality of break point angles.

7. The displacement control system according to claim 6 of ML / t / ZUZZ / UOUUÓ 1 25, characterized in that each of the break point angles is determined based on a user input.

8. The displacement control system according to claim 1, characterized in that the speed of the material handling vehicle is restricted below a temporary speed limit until the first speed limit is determined.

9. The displacement control system according to claim 1, characterized in that when the turning angle exceeds a pivot break point angle, a corresponding speed limit of the material handling vehicle is not determined based on the intrinsic properties of the material handling vehicle.

10. The displacement control system according to claim 3, characterized in that the speed limit of the material handling vehicle is determined so that the braking distance of the material handling vehicle is separated from the first limit and the second limit by at least a damping distance.

11. The displacement control system according to claim 1, characterized in that the intrinsic aspects of the material handling vehicle include at least one of the vehicle's weight, vehicle's height, vehicle's width, location of the drive wheels, and locations of the non-drive wheels.

12. A method in a computer-implemented system for controlling the movement of a material handling vehicle, the method being characterized in that it comprises: receiving, in a control system of the material handling vehicle, intrinsic aspects of the material handling vehicle; determining, based on the intrinsic aspects of the material handling vehicle and a configuration of a scanner mounted on the material handling vehicle, at least one speed limit associated with at least one turning angle range of the material handling vehicle; receiving, in the control system, a current speed of the material handling vehicle; receiving, in the control system, a current turning angle of the material handling vehicle;When the current turning angle is within at least one turning angle range and the current speed exceeds at least one speed limit associated with at least one turning angle range, generate a signal to an engine control unit to reduce the speed of the material handling vehicle.

13. The method according to claim 12, characterized in that at least one turning angle range comprises a plurality of turning angle ranges, each of the plurality of turning angle ranges being associated with a corresponding one of a plurality of speed limits.

14. The method according to claim 12, characterized in that the scanner configuration includes a first limit and a second limit that at least partially define a field of view of the scanner, and wherein at least one speed limit is determined such that the braking distance for the material handling vehicle is within the field of view when the current turning angle of the material handling vehicle is within at least one turning angle range.

15. The method according to claim 14, characterized in that it further comprises receiving, in the control system, an input that includes a damping distance, wherein the stopping distance is separated from the first limit and the second limit by a distance that is at least as large as the damping distance.

16. The method of claim 12, characterized in that the intrinsic aspects of the material handling vehicle include at least one of the vehicle's weight, vehicle's height, vehicle's width, location of the drive wheels, and locations of the non-drive wheels.

17. The method according to claim 12, characterized in that it further comprises receiving, in the control system, an input that includes a first critical point angle, wherein at least a range of rotation angles is defined at least partially by the first critical point angle.

18. A computerized control system for a material handling vehicle, the computerized control system being characterized in that it comprises: a material handling vehicle object detection system including at least one scanner having a field of view defined between a first limit and a second limit; a motor control unit; one or more processors; a memory storing one or more programs to be executed by one or more processors, the one or more programs comprising instructions for performing a method for controlling the movement of the material handling vehicle, the method comprising: receiving, in one or more processors, a current speed of the material handling vehicle and a current turning angle of the material handling vehicle; determining, based at least in part on the current speed and the current turning angle, a braking distance of the material handling vehicle;determine if the stopping distance is within the scanner's field of view; and if the braking distance is outside the scanner's field of view, generate a signal to the engine control unit to reduce the speed of the vehicle handling ML / t / ZUZZ / UOUUÓ 1 27 materials.; 19. The computerized control system according to claim 18, characterized in that it further comprises determining at least one speed limit associated with at least one range of turning angles, wherein determining whether the braking distance is within the field of view of the scanner comprises comparing the current speed with at least one speed limit when the current turning angle is within at least one range of turning angles.

20. The computerized control system according to claim 18, characterized in that upon receiving the signal from one or more processors, the motor control unit reduces the speed of the material handling vehicle by a predefined increment.

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